I have 3.0 GM block (engine). Starter bolts are offset. I've used different types of starters, big ones and the small high torque ones. I've also used new bolts and shims (shims made the problem worse). The problem I am having is the starter works fine the first few starts, then over a short period of time, the starter cracks (breaking the front (cone) of the starter). There is no electrical problem. Some people have spare tires...I have 2 spare starters in the boat..hahaha...If anyone has had a similar problem where the starter keeps on cracking...please help. Thanks...Vic.